The present invention relates to a food intake restriction device for the treatment of morbid obesity. More specifically, the invention relates to a food intake restriction device for surgical application in the abdomen of a patient for forming a stoma opening in the stomach or esophagus of the patient.
Food intake restriction devices in the form of gastric banding devices, in which an elongated restriction member in the form of a band encircles a portion of the stomach, have been used in surgery for morbid obesity to form a small gastric pouch above the band and a reduced stoma opening in the stomach. Although such a band is applied around the stomach to obtain an optimal stoma opening during surgery, some prior gastric banding devices are provided with a control means enabling minor post-operation control of the size of the stoma opening. The control means in such prior art devices as disclosed, for example, in U.S. Pat. No. 4,592,339, European Patent No. 0611561 and International Patent Application WO 94/27504, comprise an inflatable cavity in the band and an injection port in fluid connection with the inflatable cavity for adding fluid to or withdrawing fluid from the lafter. In practice, the band is made of silicone rubber which is a material approved for implantation and the fluid is a liquid such as an isotonic salt solution.
It has been found, however, that the prior bands later might dislocate downwardly on the stomach and there is an increased risk of stoma stenosis due to too limited control of the band. It has also been found that the volume of the gastric pouch above the band increases in size up to ten times after the operation. Therefore the pouch volume during surgery needs to be very small, approximately 7 ml. To enable the patient to feed the stomach with sufficient nutrition immediately after the operation considering such a small gastric pouch, the stoma initially needs to be relatively large and later needs to be substantially reduced, as the pouch volume increases. To be able to achieve acceptable control of the band, the cavity in the band has to be relatively large and be defined by a thin flexible wall, normally made of silicone material. Furthermore, the size of the stoma opening has to be gradually reduced during the first year after surgery as the gastric pouch increases in size. As indicated above, the reduction of the stoma opening by using the prior art gastric banding devices is achieved by adding liquid to the cavity of the band via the injection port to expand the band radially inwardly.
A great disadvantage of repeatedly injecting liquid via the injection port is the increased risk of the patient getting an infection in the area surrounding the injection port. If such an infection occurs the injection port has to be surgically removed from the patient. Moreover, such an infection might be spread along the tube interconnecting the injection port and the band to the stomach causing even more serious complications. Thus, the stomach might be infected where it is in contact with the band, which might result in the band migrating through the wall of the stomach. Also it is uncomfortable for the patient when the necessary, often many, post-operation controls of the stoma opening are carried out by using an injection needle penetrating the skin of the patient into the injection port.
Also the patient may swallow pieces of food that are too large and therefore cannot pass the restricted stoma opening. In this case the patient has to visit a doctor who can remove the food pieces, if the band design so permits, by withdrawing some liquid from the band to enlarge the stoma opening to allow the food pieces to pass the stoma. Then, the doctor has to add liquid to the band in order to regain the restricted stoma opening. Again, these measures require the use of an injection needle penetrating the skin of the patient, which is uncomfortable for the patient.
Another problem with the known adjustable gastric banding devices is that there is a risk of leakage from the band balloon occurring some time after the operation.
The invention provides an adjustable food intake restriction device which does not require the use of an injection needle for accomplishing post-operation adjustments of the stoma opening. Rather, the invention provides an adjustable food intake restriction device which permits post-operation adjustments that are comfortable for the patient, and which reduces the risk of liquid leaking from the device.
In accordance with a broad aspect of the present invention, a food intake restriction device is provided for surgical application in the abdomen of a patient for forming a stoma opening in the stomach or esophagus of the patient, the device comprising: an elongated non-inflatable restriction member formed into at least a substantially closed loop around the stomach or the esophagus, the loop defining a restriction opening, an adjustment device which mechanically adjusts the restriction member in the loop to change the size of the restriction opening, hydraulic operation means for operating the adjustment device, and a reservoir containing a predetermined amount of hydraulic fluid for supplying the hydraulic operation means with hydraulic fluid.
In accordance with a specific aspect of the present invention, a food intake restriction device is provided for forming a stoma opening in the stomach or esophagus of a patient, comprising: an elongated restriction member forming an expandable and contractible cavity formed into an at least substantially closed loop around the stomach or esophagus of the patient and defining a restriction opening, the size of which is reduced upon expansion of the cavity and increased upon contraction of the cavity, a reservoir containing a predetermined amount of hydraulic fluid and connected to the cavity of the restriction member, and a hydraulic operation means for distributing fluid from the reservoir to the cavity to expand the cavity and for distributing fluid from the cavity to the reservoir to contract the cavity.
Thus, there is no need for an injection port for accomplishing necessary post-operation adjustments of the restriction opening to change the size of the stoma opening. (In certain applications, however, an injection port connected to the reservoir may be provided for enabling, normally a single once-and-for-all, calibration of the predetermined amount of fluid in the reservoir.)
In accordance with a general embodiment of the invention, the reservoir defines a chamber for the predetermined amount of fluid and the hydraulic operation means changes the size of the chamber. Preferably, the hydraulic operation means comprises first and second wall portions of the reservoir, which are displaceable relative to each other to change the size of the chamber of the reservoir. The hydraulic operation means may distribute fluid from the reservoir to the cavity of the restriction member in response to a predetermined first displacement of the first wall portion of the reservoir relative to the second wall portion of the reservoir and to distribute fluid from the cavity to the reservoir in response to a predetermined second displacement of the first wall portion relative to the second wall portion.
The first and second wall portions of the reservoir may be displaceable relative to each other by manual manipulation thereof, such as by manually pushing, pulling or rotating any of the wall portions in one direction, or alternatively, may be displaceable relative to each other by a device powered magnetically, hydraulically, or electrically (e.g. by an electric motor). In this embodiment no pump is used, only the volume of the reservoir is varied. This is of great advantage compared to the solution described below when a pump is used to pump fluid between the reservoir and the adjustment device because there is no need for a non-return valve and it is still possible to have fluid going both to and from the reservoir.
In accordance with a particular embodiment of the invention, the hydraulic operation means comprises an activatable pump for pumping fluid between the reservoir and the cavity of the restriction member. The pump preferably comprises a first activation member for activating the pump to pump fluid from the reservoir to the cavity of the restriction member, and a second activation member for activating the pump to pump fluid from the cavity to the reservoir. The first and second activation members may be operable by manual manipulation thereof, such as by manually pushing, pulling or rotating any of the activation members in one direction. At least one of the activation members is constructed to operate when subjected to an external pressure exceeding a predetermined magnitude.
As an alternative to the manual manipulation, at least one of the first and second activating members may be operable by a device powered magnetically, hydraulically, or electrically (e.g. by an electric motor). The pump may pump fluid both to and away from the adjustment device or hydraulic means controlling the adjustment device. A mechanical manual solution is proposed in which it is possible to pump in both directions just by pushing an activating member in one direction. Another alternative is a pump pumping in only one direction and an adjustable valve to change the direction of fluid to either increase or decrease the amount of fluid in the reservoir. This valve may be manipulated either manually, mechanically, electrically, magnetically, or hydraulically. Any kind of motor could be used for the different operations s well as wireless remote solutions.
Wherever a magnetic means is utilized according to the invention it may comprise a permanent magnet and a magnetic material reed switch, or other suitable known or conventional magnetic devices.
In accordance with another particular embodiment of the invention, the hydraulic operation means comprises a servo means, suitably including a hydraulic device. Alternatively, the servo means may include magnetic or electric means. Preferably, the servo means comprises a servo reservoir defining a chamber containing servo fluid and the hydraulic operation means comprises first and second wall portions of the servo reservoir, which are displaceable relative to each other to change the size of the chamber of the servo reservoir. The same principle will apply for the servo reservoir as for the earlier described reservoir wherein the volume in the servo reservoir may be increased or decreased by a first or second displacement of the first wall portion relative to the second wall portion of the servo reservoir and thereby control the earlier described reservoir and thereby indirectly control the restriction opening. The first and second wall portions of the servo reservoir may be displaceable relative to each other by manual manipulation thereof, such as by manually pushing, pulling or rotating any of the wall portions of the servo reservoir in one direction. Alternatively, the first and second wall portions may be displaceable by magnetically, hydraulically or electrically powered devices. These powered devices may all be activated by manual manipulating means preferably located subcutaneously. This activation may be indirect, for example via a switch.
Advantageously, especially when manual manipulation means are used, a servo means system could be used. With servo means less force is needed for controlling the adjustment device. Hydraulic operation is preferably used with servo means. One example is a closed system that controls another closed system in which the hydraulic means of the adjustment device is incorporated. Minor changes in the amount of fluid in a reservoir of the first system could then lead to major changes in the amount of fluid in a reservoir in the second system. Consequently, the change in volume in the reservoir of the second system affects the hydraulic operation of the adjustment device which is incorporated in the second closed system. The great advantage of this servo system is that the larger volume system could be placed inside the abdomen where there is more space and still it would be possible to use manual manipulation means of the smaller system subcutaneously. The servo reservoir could control the reservoir of the larger volume. The servo reservoir could be controlled directly or indirectly by a fluid supply means. The fluid supply means may be a small reservoir, which may be placed subcutaneously and may be activated by manual manipulation means controlling the servo reservoir, or other suitable device.
Preferably, the fluid supply means comprises hydraulic means and a fluid supply reservoir defining a chamber containing fluid, and the hydraulic operation means comprises first and second wall portions of the reservoir, which are displaceable relative to each other to change the size of the chamber of the fluid supply reservoir. The hydraulic operation means may distribute fluid from the fluid supply reservoir to the servo reservoir in response to a predetermined first displacement of the first wall portion of the fluid supply reservoir relative to the second wall portion of the fluid supply reservoir and to distribute fluid from the servo reservoir to the fluid supply reservoir in response to a predetermined second displacement of the first wall portion relative to the second wall portion. The wall portions of the fluid supply reservoir may be displaceable relative to each other by manual manipulation means or be displaceable relative to each other by manual manipulating means for pushing, pulling or rotating any of the wall portions of the fluid supply reservoir in one direction. Alternatively, the wall portions of the fluid supply reservoir may be displaceable relative to each other by magnetic means, hydraulic means, manually manipulated means, or electrical control means including an electric motor. The magnetic means, hydraulic means, or electrical control means may all be activated by manually manipulated means preferably located subcutaneously. This control may be indirect, for example via a switch.
Even in the broadest embodiment of the invention the adjustment device may comprise a servo means. The servo means may comprise a hydraulic operation means, an electric control means, a magnetic means, mechanical means, or a manual manipulating means. The hydraulic operation means, electric control means, mechanical means or magnetic means may be activated by manual manipulating means. Using a servo system will save the use of force when adjusting the adjustment device which may be of importance in many applications.
All systems according to the invention may be controlled by a wireless remote control means.
In accordance with an advantageous embodiment of the invention, there is provided a wireless remote control means for controlling the hydraulic operation means and comprising a separate signal transmitting means and a signal receiving means for controlling the hydraulic operation means in response to signals received from the signal transmitting means. Preferably, the remote control means comprises a motor for operating the hydraulic operation means and an energizer unit for providing energy, and the signal receiving means comprises a control unit powering the motor with energy provided by the energizer unit in response to signals received from the signal transmitting means. In this case the energizer unit may be a battery. The wireless remote control may control the adjustment device and any type of hydraulic operation means including servo means and fluid supply means. The remote control also could control any of the other described embodiments including any kind of servo means. Advantageously, the signal transmitting means also transmits electromagnetic wave signals and the energizer unit draws radiant energy from the electromagnetic wave signals as they are transmitted to the signal receiving means and transfers the radiant energy into electric energy for powering the electric motor.
To expand the field of application, the energizer unit may comprise a rechargeable electric power supply, such as a capacitor, for storing the electric energy and the control unit may power the electric motor, for instance a stepping motor, with energy from the rechargeable electric power supply in response to signals received from the signal transmitting means. In an initial charging step the rechargeable power supply can be charged over a relatively long time (e.g. a few seconds up to a half hour) without powering the electric motor. In a following operating step, when the power supply has been charged with sufficient energy, the control unit powers the electric motor with energy from the charged power supply to operate the adjustment device, so that a desired change of the patient""s stoma opening is achieved. If the capacity of the power supply is significant to achieve the necessary adjustment in one single operating step, the above steps may conveniently be repeated until the desired adjustment is achieved.
As an alternative, the energizer unit may comprise a battery, an electrically operable switch connecting the battery to the signal receiving means in an xe2x80x9conxe2x80x9d mode when the switch is powered and to keep the battery disconnected from the signal receiving means in a xe2x80x9cstandbyxe2x80x9d mode when the switch is unpowered, and a rechargeable electric power supply for powering the switch. The control unit may power the electric motor with energy from the battery in response to signals received from the signal transmitting means, when the switch is in its xe2x80x9conxe2x80x9d mode. Suitably, the energizer unit may transfer the radiant energy into a current for charging the rechargeable electric power supply, such as a capacitor.
The energizer unit may comprise a coil connected to the signal receiving means for inducing an alternating current as electromagnetic wave signals are transmitted through the coil to the signal receiving means and a rectifier for rectifying the alternating current.
The non-inflatable embodiment of the restriction member and the adjustment device utilized according to the invention may be as shown in a copending application entitled xe2x80x9cMechanical Food Intake Restriction Devicexe2x80x9d filed the same date as this application (attorney docket 2333-11), the disclosure of which is hereby incorporated by reference herein.
The invention also relates to a method of treating morbid obesity, comprising: (a) Surgically implanting in the abdomen of a patient with morbid obesity a food intake restriction device which forms a stoma opening in the stomach or esophagus, by forming an elongated restriction member (e.g. of bio-compatible material, or covered with bio-compatible material) into at least a substantially closed loop around the stomach or the esophagus of the patient, the loop defining a restriction opening; and then (b) when necessary for the patient""s health or desired progress, in a non-invasive procedure, hydraulically acting on the restriction member to change the size of the restriction opening. Where the restriction member comprises a cavity which can be expanded and contracted by the supply of hydraulic fluid thereto, then (a) may be practiced in part by implanting in the patient a reservoir containing a predetermined amount of hydraulic fluid and connecting the reservoir to the cavity and a hydraulic operation means for distributing fluid from the reservoir to the cavity; and (b) may be practiced by controlling the hydraulic operation means from a point outside the patient""s body without physically penetrating the patient""s body. Where the restriction member is acted upon by an adjustment device which mechanically adjusts the loop, then (a) may be practiced in part by implanting in the patient the adjustment device, implanting a reservoir containing a predetermined amount of hydraulic fluid and connecting the reservoir to the cavity, and implanting a hydraulic operation means for distributing fluid from the reservoir to the cavity; and (b) may be practiced by controlling the hydraulic operation means from a point outside the patient""s body without physically penetrating the patient""s body to control the adjustment device so that the size of the restriction opening is changed. This may be done manually, remotely, by remote control, or in the other described manners.
In the method (a) may be practiced by laparoscopic techniques, e.g. by (i) inflating the patient""s abdomen with gas by penetration of the patient""s skin, (ii) introducing at least two laparoscopic trocars into the abdomen to introduce the elongated restriction member and one or more medical instruments, and then (iii) forming the elongated restriction member into the at least substantially closed loop.
It is the primary object of the present invention to provide an advantageous yet relatively simple assembly and method for treating morbid obesity in a substantially non-invasive manner after initial surgical implantation of a restriction member. This and other objects will become clear from the detailed description and from the appended claims.